Calculating time difference in MySQL but taking events into account -


i have table structured this

index - date ------ time ----- status 1       2015-01-01  13:00:00   start 2       2015-01-01  13:10:00   continue 3       2015-01-01  13:20:00   continue 4       2015-01-01  13:30:00   end 5       2015-01-01  13:30:00   ready 6       2015-01-01  13:40:00   start 7       2015-01-01  13:50:00   continue 8       2015-01-01  15:00:00   end

and count time between start , end (ie. index 1-4 30min, 6-8 20min), taking account first start , first end, query doesn't choose time difference of index 1-8. query used calculate time difference between 2 statues (start-end) , show result multiple instances of start-end without them getting batched 1 event?

for each start, use query next end time. then, calculate difference. logic this:

select t.*, timestampdiff(second, dt, next_dt) (select t.*, addtime(t.date, t.time) dt,              (select addtime(t2.date, t2.time)               table t2               addtime(t2.date, t2.time) > addtime(t.date, t.time) ,                     status = 'end'               order addtime(t2.date, t2.time) desc               limit 1              ) next_dt       table t       status = 'start'      ) t

this assumes date , time columns stored using proper database types (date , time). if storing them else, have needlessly complicate logic convert them internal formats.


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